We want to unify some people from different parts of a country, e.g. farmers.

These people have similar interests.

Now, consider my concocted sentences:

We should bring people with same interests under a roof so that ... .

We should bring people with same interests under an umbrella so that ... .

The above sentences have been translated word by word from my native language. I want to know whether English speakers have same phrases including "umbrella" or "roof"? If so, I will be happy to know about it.

More:

I know I can use the verbs like "unify", but I want to use idiomatic phrases. So, other suggestions will also be appreciated.